Within the EU-27, Italy is one of the countries with the highest levels of inequality and intergenerational transmission of disadvantage. This paper aims to verify the effect that different conditions of vulnerability, such as a low socio-economic family background (SEB) and a prolonged period in the school-work transition, have on individuals’ future careers. The analysis is based on a dataset obtained by matching the EU-SILC data with the administrative archives of the National Institute of Social Security. We measured the determinants of the duration of the waiting time to the first job (STWT). The Cox survival function shows that growing up in a disadvantaged family context strongly increases the probability of longer STWT. We also explore the effects of this duration, combined with the family socio-economic background, on the subsequent ten years of job career. A longer STWT increases the probability of experiencing longer spells of unemployment or inactivity, leading to more precarious working conditions. The relationship is complex and non-linear, with a diminishing negative impact on career stability as STWT duration increases, especially for individuals with high SEB.